After 12 years of technical obstacles and scepticism, China has successfully evaluated artillery-launched drones capable of surviving the crushing load in a 155mm (6 inches) cannon shell.
5 live-fire trials at a western test base validated the drones endured launch forces exceeding 3,000 times their own weight similar to 35 adult African elephants on a person.The advance centres on a pyrotechnic ejection system co-developed by the Shaanxi Applied Physics and Chemistry Research Institute, the Chinese flying force, and defence professional Norinco.This highly reputable but inexpensive system manages a sequence of precisely timed detonations to separate the drone from itsartilleryshell mid-flight while protecting it from aerodynamic damage all without electronic controls.These drones can reach ranges going beyond 10 kilometres (6.2 miles) in seconds, multiply flight variety, substantially conserve power usage and extend loiter time, the team, led by senior engineer Huang Yunluan, wrote.First proposed by Chinese military researchers in 2013, a cannon-launching design called Tianyan (sky eye) acquired attention in a new-concept aircraft competition, according to state-run China News Service.
The idea dealt with decade-long doubts over delicate components making it through artillery launches.As just recently as last year, military experts informed the military channel of state broadcaster CCTV that electronics might not stand up to the ultra-high g-forces or gravitational force equivalent of weapons launch, hindering progress of such technology.Undeterred and supported by long-term government and military funding, scientists and engineers have now overcome these hurdles.Huangs team deserted initial attempts to use electronic controls for separation, deciding instead for an extremely trusted, chip-free pyrotechnic gadget to achieve the needed complex and precise actions.A look within at the artillery-launched drone system.
Photo: Shaanxi Applied Physics and Chemistry Research InstituteThe devices strength starts with its solidified stainless-steel frame, crafted to sustain stresses of as much as 1,100 megapascals (MPa).
Inside, lead azide and boron-based dynamites remained intact even when subjected to extreme forces.
Rigorous hammer effect tests proved the system survives loads 36,000 times higher than gravity for over 20 milliseconds.
Ignition reliability hinges on a smart maze channel design, according to Huangs team.Four exactly spaced 1mm (0.04 inches) holes reduce devastating detonation pressure substantially while still enabling flames to propagate.
A grooved manager structure avoids explosive debris from obstructing these critical pathways.The entire separation series runs through an eight-stage domino effect requiring no electronics or external power.
It begins with fuse detonation, progressing through bulkhead ignition, generating a powerful axial thrust to eject the drone capsule, triggering a delayed igniter and lastly launching another radial thrust to shed protective panels.In temperature extremes ranging from -50 degrees Celsius (-58 degrees Fahrenheit) to 80C and throughout bulkhead thickness variations from 1 to 4mm (0.04 to 0.15 inches), the ignition system fired flawlessly while avoiding blockages.Most critically, all five ground detonation tests and five live artillery launches attained perfectly timed separation of drone components, showing the system could stand up to loads a minimum of 3,500 times to gravity in real-life settings.These drones will undoubtedly hold a pivotal position in future military advancement, Huang and his coworkers wrote.Source: South China Morning Post